The loss sliced Boston's division lead to three games over the second-place New York Yankees, who beat Tampa Bay 3-2.

Oakland, which owns the majors' worst road record (22-48), snapped an eight-game losing streak away from home. The A's had dropped their last seven at Fenway Park.

Dustin Pedroia had three singles for Boston to extend his hitting streak against the A's to 26 games. The Red Sox had won five of six.

Jharel Cotton (8-10) picked up the win, allowing three runs in five innings. He entered 1-7 with an 8.00 ERA in night games.

Five relievers held Boston scoreless the rest of the way.

Doug Fister (5-8) was tagged for six runs and six hits in four innings. He was 3-1 with a 1.50 ERA in his previous four starts.

A night after getting routed 11-1 by the Red Sox, Oakland built a 6-1 lead by scoring four in the first and two in the third.

Lowrie had an RBI triple and Khris Davis a run-scoring single in the first before Olson hit his homer into the A's bullpen.

Boston scored a run in the first on Mookie Betts' RBI grounder and one in the third on Andrew Benintendi's RBI double.

Banner Ejection

A few fans seated above the Green Monster unfurled a banner during the fourth inning and were escorted from their seats. The sign — draped over the top middle of the 37-foot Monster — had a black background with white letters that read: "Racism is as American as Baseball."

It's not the first time that the Red Sox have responded to the topic of racism at the ballpark.

Earlier this season, Orioles center fielder Adam Jones said after a game on May 1 that he was the victim of racial slurs and had peanuts thrown at him during the game.

The next day, Jones received a personal apology from Boston team president Sam Kennedy on behalf of the club. When he stepped up for his first at-bat of the game, he was also given extended applause from the Fenway crowd.

Red Sox pitcher Chris Sale stepped off the mound to allow the applause to continue.

"Just appreciative that action was taken and not everybody feels the same way as selected people," Jones said.

Papi's Position

The Red Sox announced they have reached a long-term agreement with retired slugger David Ortiz that "should link him with the organization forever."

Ortiz is expected to act as a mentor for current players, help recruit players, make appearances and help develop business for Fenway Sports Management and its partners.

Trainer's Room

Red Sox: LHP David Price (left elbow inflammation) threw his second simulated game. "He's in the process of building up arm strength," manager John Farrell said. "I thought he threw with good velocity." Price, who has seldom spoken to the media while working his way back, said: "I don't know how many more times I have to do a live BP, but if I come tomorrow and feel fine, I don't know what else I have to do."